Form and rules
How it works
Some verbs normally take -ing, others take to-infinitive, so learn their complementation patterns.
Remember/forget doing looks back at a memory; remember/forget to do concerns a necessary action.
Stop doing means end an activity; stop to do means pause another activity for a purpose.
Try doing suggests an experiment/possible solution; try to do emphasizes effort to achieve something.
Regret doing looks back with regret; regret to say/tell/inform is a formal way to introduce bad news.